The bio: A native Garden Stater, Christie grew up middle-class and graduated from the University of Delaware before earning a law degree at Seton Hall. While working in private practice, he first waded into politics as a county freeholder in the 1990s. In 2002, he became the state’s top federal prosecutor and burnished his credentials by taking tough stances on corruption, terrorism and white-collar crime. After his term ended in 2008, he launched an upstart gubernatorial bid that ultimately unseated embattled Gov. Jon Corzine in a reliably blue state. Since entering the statehouse, Christie has become a conservative sensation, beloved by the base for his penchant for YouTube-friendly diatribes against teachers’ unions, hecklers and government bloat. GOP business leaders urged Christie to mount a presidential run of his own, but Christie declined; instead, he endorsed Romney early and served as a crucial surrogate in Iowa and New Hampshire.

The case for: The voluble governor would inject a dose of brio into Romney’s straitlaced campaign. Few, if any, among the top-tier VP contenders can match Christie’s panache or the excitement he generates among Tea Partyers. In a recent Quinnipiac poll, Christie was respondents’ top pick to fill out the GOP ticket, topping Marco Rubio and Paul Ryan; independents favored Christie’s selection, calling him a good pick by a 33-18 margin.

There is also some evidence that Christie’s selection could mobilize conservatives still leery about turning out for Romney. An April 19 survey by the Democratic firm Public Policy Polling found that Christie, of a group that included Rubio, Ryan, Jeb Bush and Mike Huckabee, did the most to improve Romney’s prospects against Obama, nudging him from a three-point deficit to a 49-49 deadlock. About one-third of Republicans either don’t like or remain ambivalent about Romney, says PPP’s Tom Jensen. “Romney is going to have to be careful that he doesn’t take for granted that the base will turn out… For a lot of those folks, there’s a sense he’s not that tough. Christie appeals to them as someone who could complement Romney.”

Unlike the wonky Midwesterners Romney may consider — a group that includes Rob Portman, Ryan and Mitch Daniels — Christie’s brash style and modest upbringing offer a stark juxtaposition with the presumptive nominee. “Chris Christie is a different kind of guy — white working-class, a tough guy, the Jersey street smarts. He’s got a different kind of appeal,” says political analyst Stuart Rothenberg. Christie would infuse the ticket with star power and shore up his right flank.

The case against: Tapping Christie would be an uncharacteristic gamble for Romney, whose buttoned-up campaign brain trust in Boston might not be comfortable with the governor’s freewheeling style. Christie strayed off message a couple of times during the primaries, such as when he suggested that Romney should stop dithering and release his tax returns. In addition, the nominee might chafe at the prospect of a megawatt VP. “Christie has a lot more personality than Romney,” Jensen says. “You want a running mate who helps you, but not someone who’s going to overshadow you.”

Still, the stylistic problems Christie’s selection could create may prove less less important than simple geography. Christie hails from a blue state, and despite an approval rating in the 50s, he would be unlikely to put New Jersey in play for Romney. It would also create a ticket of two comparatively moderate Northeasterns for an increasingly conservative party that runs strongest in the South and West. That’s not a recipe for Electoral College success, even if Christie would do more than most others to galvanize the base.

What’s more, Christie may not clear the only bar Romney has publicly set for his veep pick. “The one quality that comes to mind immediately is that you want someone who, without question, could lead the country as president if that were necessary,” Romney told CNBC’s Larry Kudlow. “I think all of the political considerations pale in comparison with the consideration of who has the capacity to lead America at a critical time. And I hope if I’m the president that eventuality would never occur. But that has to be the key consideration.” This is, of course, a political answer: no nominee is apt to suggest that his pick will be driven by politics. But in the post-Palin landscape, tapping a dull, wizened bureaucrat who’s viewed as ready to lead may be the best politics. Romney surely remembers that just months ago, Christie rebuffed his party’s entreaties by saying he didn’t feel ready to serve as president. It’s hard to imagine that much has changed.